Known organic conductors exhibiting super conductivity under normal pressure include bis(ethylenedithio)tetrathiafulvalene (hereinafter abbreviated as BEDT-TTF) compounds as disclosed in JP-A-61-277691 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), dimethyl(ethylenedithio)diselenathiafulvalene (hereinafter abbreviated as DMET) compounds as disclosed in JP-A-63-246383, and methylenedithiotetrafulvalene (hereinafter abbreviated as MDT) compounds as reported by G. C. Papauassiliou, et al. in International Conference on Science and Technology of Synthetic Metals, June 26-July 2, 1988, Santa Fe.
Further, organic conductors known to have a critical temperature (Tc) of 10 K or higher include cation radical salts, e.g., (BEDT-TTF).sub.2 Cu(NCS).sub.2 and a deuteration product thereof, (BEDT-TTFd.sub.8).sub.2 Cu(NCS).sub.2, as described in H. Urayama, et al., Chem. Lett., 55 (1988).
Synthesis and crystal growth of organic conductors or super conductors are conducted by an electrolytic method in which an electron donating material (donor), e.g., BEDT-TTF, and an electron accepting material (acceptor), e.g., I.sub.3.sup.- and Cu(NCS).sub.2.sup.-, are dissolved in an organic solvent, and an electrical current of from 0.5 to 2 .mu.A is passed therethrough to effect an electrochemical oxidation-reduction; or a diffusion method utilizing diffusion of the donor and acceptor.
However, the electrolysis method and diffusion method require a considerable time for synthesis and crystal growth of organic conductors. For instance, it takes from 1 week to 2 months to obtain crystals having a size of about 1 to 2 mm.